MathDB
ASU 523 All Soviet Union MO 1990 [n/1!] + [n/2!] + ... + [n/10!] = 1001

Source:

August 14, 2019
floor functiondiophantinenumber theory

Problem Statement

Find all integers nn such that [n1!]+[n2!]+...+[n10!]=1001\left[\frac{n}{1!}\right] + \left[\frac{n}{2!}\right] + ... + \left[\frac{n}{10!}\right] = 1001.